Power supply to metallurgical plant with calculation of induction crucible furnace

Introduction

Power supply systems of industrial enterprises consisting of networks with voltage up to 1000 V and above and transformer, converter, and distribution substations are used to provide electricity in the required quantity and quality.

Consumers of electricity have their own specific features, which is due to certain requirements for their electricity supply - reliability of power supply, quality of electricity, redundancy and protection of individual elements, etc. When designing, constructing and operating power supply systems of industrial enterprises, it is necessary to take into account the technical and economic aspects when making voltage selection, determining electrical loads, choosing the type, number and power of transformer substations, types of their protection, reactive power compensation systems. When selecting the voltages of the supply lines, the location and number of transformer substations, control systems, protection - there should be provided opportunities to improve the technological process and increase capacity.

Calculation of electrical loads

1.1. General information and features of the process..

Determination of design loads of industrial enterprises is based on the following provisions:

a) most mechanisms operate with variable load and the electric motors of these mechanisms, selected according to the heaviest modes, are unloaded a significant part of the time.

b) not all electric receivers are switched on simultaneously and constantly. The time of their operation and shutdown depends on the technological mode of production.

c) at certain times, the load can exceed the average power value due to a change in the process. It is necessary to determine the maximum possible power consumption for a period of time. This power is called maximum.

d) when large lighting receivers are switched on, as well as when asynchronous motors with short-circuited rotor are started, power consumption increases above the average and minimum values.

When calculating electrical installations, there is not always a load schedule and therefore they resort to design factors. You can use them to define the basic parameters of a load schedule.

Calculation of electrical loads is necessary when selecting the number and power of transformers at substations. In order to calculate the design loads in the electrical mains up to 1000 V, the following values must be determined:

a) total, nominal, active and reactive power of power electric receivers by individual groups.

b) group utilization factors and total average power loads (active and reactive) for the busiest shift.

c) effective number of electric receivers, maximum factor, maximum active power, reactive and full power by individual groups.

d) design power of lighting loads.

e) maximum values of active, reactive, full power throughout the substation.

When determining electrical loads of groups of electric receivers, the calculated value is the average power of the most loaded shift.

The average active or reactive power for the busiest shift is determined by the electric energy consumption. According to PUE, the maximum power is taken as the design active power, which is the design value for selecting all power supply elements for heating conductors. The design active power corresponds to such a long constant load, which is equivalent to the expected variable load for the heaviest thermal action.

In this degree project, the calculation of electrical loads will be carried out using ordered diagrams. First, select and arrange the equipment in the workshop. Next, we divide the equipment by distribution cabinets and determine the number of receivers in each distribution cabinet.

Чертежи к диплому.dwg